Time gauge for photographic developing, etc.



H. A. MASAC.

TIME GAUGE FOR PHoToGRAPHlc DEVELOPING, ETC.

APPLiCATlON FILED PR. 7. 1920.

Patented June 27, 1922.

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HGWARD A. MIASAC, 0F LOS ANGELES, CALIFORNIA.

To all whom t may concern.'

Be it known that I, HOWARD A. MAsAC, a citizen of the United States,residing at Los Angeles, inthe county of Los Angeles and State ofCalifornia, have invented new and useful Improvements in Time Gauges.for Photographic Developin, Ete., of

which the following is a spec' cation.

This invention is a time gau e for photographic `developing and the e,and has for its object to provide means for measur- .although it-will bereadily understood that the invention is applicable to the developmentof any photographic plates and the like, the graduations upon the gauge,if necessary, being altered for the particular use for which the gaugeis adapted.

The drawing, forming a part of this specication, is a front elevation ofa gauge constructed in accordance with the invention. Y Y

The gauge is illustrated as comprisingla base l upon which is mounted aclosed tube 2 terminating at its lower end in a bulb 3,

the tube being positioned lengthwise of the base 1 by suitablebrackets4'and'prefer ably,`being provided with a protecting casing 5'over the bulb 3. The tube and bulb are adapted to contain any suitablemedium which is expansible proportional to temperature variations, suchas mercury, for example.

Graduations are provided upon the base of the gauge along the tube 2,these graduations being adapted to indicate in terms of l periods oftime various temperatures indicated by the column of the expansiblemedium within the tube 2. In the present instance, and as illustrating apractical embodiment of the invention, the graduations shown at 6 mayeach be arranged to indicate a rise in temperature of one degree F,eleven -of such/graduations being, preferably, pro' indications for thisT IME GAUGE FOR PBOTOGRAPHIC DEVELOPING, ETC.

Specication of Letters Patent. v Patented June 2'?, 1922, Applicationle'd April 7, 1920. Serial No. 371,979.

Each of these graduations is marked to,

represent a period of time comprising 20 seconds 'between adjacentgraduations, the period of time starting at 3 minutes and 20 seconds fortheupper- Imost graduation which re resents a'Vtemlperature of 70 andextending downwardly therefrom to the lowermost vgraduation representing6 minutes and 40 seconds. The minutes represented by the graduations 6are, preferably, marked upon the base of the gauge at said graduationsat one side of the tube 2, and the seconds indicated by the graduationare, preferably, the base of the of the tube 2. y

VAbove the 'numerals representing the minute graduations theword"Minutes .or an abbreviation thereof is, preferably marked uponmarked upon the base ofthe gauge as shown gauge at the opposite sidel at7, and similarly the word Seco-nds7 or an abbreviation thereof ismarkedupon the` base of the "gaugeA as shown at '8 above the numeralsrepresenting the second gradu'a-- tions. The'mi'ddle graduationof theseries indicating a temperature of 65- F; .and marked to indicate 5minutes is, referably, alsov marked with the word Np shown at 9.'

In use the gauge, as thus constructed, is

adapted to be inserted in a developin -solution which is to be employedfor deve oping photographic plates, in the present instance X-rayplates. The temperature of the solu-v tion should always be'betweenii()oand 70 F. inclusive and willthereforebe registered on the gauge, and thelength-ottime which a plate should be left in the developing solutionwill be indicated by. the rising column of mercury uponthe'graduationsof the gauge; the length of time which a plate should beleft in the developing solution increasing converselyto the temperatureof the solution from a--period 'ot time of 3 minutes and 20 seconds fora solution at a temperature of 70 F. to. a period of timel of 6 minutesand seconds for a solution at a temperature of 60" F. Thus it will'beseen that the proper length of time .for developingv a plate will beinstantlyshown upon the gauge when the latter is dipped in thedeveloping solution Without necessitating any computations. n

Various changes may he made Without 5 departing from 4the spirit of theinvention as claimed.

What is claimed is: A gauge comprising a temperature responsive mediurnhavlng a scale associated therewith and graduated from six 10minutesforty seconds to I"three minutes twenty seconds throughout whatcorresponds to a temperature increase from sixty degrees to seventydegrees F. inclusive.

In testimony whereof I have signed myf15 name to this specification

